Evaluation of Collateral Ligament Injury

No validated rules have been formulated for the use of radiography in patients with suspected ligament injuries, but a decision tree can be used as a guide (Figure below).
Although plain radiographs may be useful in the initial diagnosis of these injuries, magnetic resonance imaging (MRI) is becoming the preferred diagnostic method and is rapidly replacing other techniques as the study of choice for the evaluation of knee injuries. However, the routine use of MRI has been questioned because of its significant cost ($600 to $1,200) and the high accuracy of clinical examination in diagnosing some injuries.